Camel-core is the basic module of apache camel. It contains the public API and the Java DSL and several implementation packages.
The most important packages are:
component
Some simple components like bean or log. You will find most components in the other camel modules
impl - implementation
Implementation classes for model and camel
processor
Definitions and implementations of many EAI patterns
model
Contains the classes that form the java DSL. The central class is the RouteBuilder
spi - service provider interfaces
Interfaces to add plugins to maven like the TypeRegistry or Lifecycle
camel
Base package for camel. Defintions like Message and CamelContext can be found there.